Waves, ice and runoff pull soil out from under shoreline rock a little at a time. Eventually the stone sinks, the bank caves in and you lose property. The fix most rip rap jobs rely on is a layer of double needle punched non woven geotextile between the soil and the stone.
Why fabric goes under rip rap
Rock alone does not stop erosion. Water moves through the gaps between stones and carries fine soil out with it. Non woven geotextile lets water pass through while holding the soil in place, so the bank stays put and the rock stays on top of it instead of sinking in.
Which weight to use
Shoreline work is hard on fabric. Stone gets dropped on it, ice pushes on it, and waves move it. That is why heavier fabric is the usual pick:
- 8 oz non woven: our heaviest, with 535 lb CBR puncture and 205 lb grab tensile. The best choice under larger rip rap and on banks that take wave or ice action.
- 6 oz non woven: 410 lb CBR puncture. Works for smaller stone, calmer water like ponds, and sheltered banks.
Our 4 oz is a great drainage fabric, but it is lighter than most shoreline jobs call for.
Installation steps
- Grade the bank to a stable, even slope and remove roots, sticks and sharp debris.
- Roll the fabric down the slope (top to bottom), not along it, so water runs over the overlaps instead of into them.
- Overlap seams by at least 12 to 18 inches, with the upslope piece on top.
- Anchor the top edge in a shallow trench and backfill it. Key the bottom edge into the lake or stream bed as far as you can.
- Pin the fabric with landscape staples to hold it while you place stone.
- Place rock starting at the bottom. Don't drop large stone from height onto the fabric. A layer of smaller bedding stone first helps protect it.
Tips
- Leave enough fabric at the top to wrap back over the edge of the rock, so runoff from the yard can't wash out behind it.
- Keep the fabric covered. Our non woven is UV stabilized (70% strength retained after 500 hours), but it is designed to be buried, not left in the sun.
Shop non woven geotextile. Every order ships free. Questions about your shoreline project? Send us a message.
Note: Work along lakes, rivers and wetlands may need a permit in some areas. If you are unsure, check with your local natural resources office.
